Manufacture oe bodies from metals having a high melting point



Oct. 5 4, 1926.

, A. E. VAN ARKEL MANUFACTURE 6F BODIES FROM METALS HAVING A HIGH MELTING ,POIIN'I' Filed Jan. 15 1923 iatented Dot. 5,. i926.

ANTCN EIDUARD VAN ARKEL, 9F EINDHOVEN, NETHERLANDS, ASSIGNQR, BY MESNE ASSIGNMENTS. TO GENERAL ELECTRIC COMPANY. A CGRBORATION OF NEW YORK.

IvIANUFACTUR-E OF BGDIES FROM METALS HAVING A TXIGH MELTING POINT.

Application filed January 15. 1923. Serial No.

This invention relates to an improved manufacture of ductile bodies of tungsten or other refractory metals and comprises heating a single crystal of metal in an atmosphere of a volatile and dissociable ompound of a refractory metal at a tempera ture which is between that at which said compound dissociates and that at which the dissociated metal ceases to associate with the metal of said crystal in such a way that the latter grows larger while retaining its single crystal structure. Single crystals of retractory metal hitherto known have a diameter not larger than about 0.1 millimeter, in any case less than 1 millimeter.

The dissociable compound of the refractory metal can be associated with small quantities of other substances which are adapted to form with the refractory metal a single crystal. The crystal to be treated can be placed in a continuous current of the vapor of the dissociable compound.

The cross-section of the crystal treated according to this invention increases in a very regular manner, till only practical considerations make it necessary to stop. The body obtained is so ductile that it may be immediately shaped into any desired form by mechanical operations such as hammering or rolling or drawin For manutacturing bodies of tungsten according to one embodiment of the invention, a tungsten crystal is heated in an atmosphere of chloride of tungsten to a temperature between 1200 and 2400 C. The metal dissociating from the chloride settles on the tungsten crystal, so that the latter increases in cross-section While remaining only a single crystal. For manufacturing wires, threads, ribbons or plates the original body -is allowed to increase in size in the atmosphere of chloride to the extent desired. The body obtained in this way, may be gi en the desired shape by mechanical treatment. Thus wires for electric lamps may be manufactured directly from such ductile material and strong wires can be obtained after further mechanical treatment.

The original crystal instead of being a crystal of the same material as the final ductile body may be a crystal of another metal or a metal alloy, provided the crystal form of this metal or alloyis isomorphous with that of the material of the duetile body. In this case the core may be re- 612,764, and in Great Britain March 24, 1922.

moved in any known manner after the formation of the body.

It may be useful, in order to improve the properties of the final product, to add to the atmosphere in which the relractor metal such as tungsten is treated. all quantitles of substances such as iron, nickel, phosphorous, or silicon. The additional substances must be such as can form a single crystal with the refractory metal, without disturbing the uniform crystallization. The substances are added by incorporating them in a Volatile state in the atmosphere in which the cr heated.

in the accompanying drawing a device is diagrammatically represented by way of example for use in carrying out the process according to the invention.

In this drawing, 1 is a vessel in which an atmosphere of chloride of tungsten is provided. This vessel is closed by two coversQ. Through each of the covers a tungsten rod is inserted and these rods support at their ends a single tungsten crystal 4. The vessel 1 is provided with a conduit 5 through which it can be exhausted. The vessel rests on supports 9 in a furnace 8. The interior of the furnace is maintained 'at such a temperature that the chlorideot' tungsten does not condense on the walls of the vessel 1. The heating of the vessel may be effected by a hot current of air, entering through a conduit 11 and leaving through a conduit 12, but the furnace can be heated in any other suitable way.

A cup -6 filled with tungsten powderis placed in the vessel. The tungsten powder may contain some additional substance as hereinbefore mentioned.

After the vessel is exhausted and filled with vapour of chloride of tungsten, the body 4 is heated to about 1500 to.1600 C. by an electric current, Whilst the powder in the cup 6 is heated in some Way to a temperature of 300500 C. According to the drawing the tpowder is electrically heated by means 0 a resistance-wire 7. The vapour then dissociates at the surface of the body 4 on which it deposits tungsten, while the liberated dissociation-products combine with the powder in the cup 6 to form new compounds capable of dissociation. 4

The Way of heating the body 4 and the powder may be varied according to circumstances. It is not necessary that the powder from the powder to the crystal in a circulating process. Instead of tungsten powder it is possible to usetungsten in any other form (the temperature to which it is heated, being varied accordingly). while chloride of tungsten can be replaced by other Volatile tungsten compounds, which are capable of dissociation.

It is to be understood. that although the process is particularly described for manufacturing bodies of tungsten, the invention is also practicable for other refractory metals, such as molybdenum, tantalum and the like, which are able to form compounds that are dissociable at a temperature below the melting point-of the metal.

lVhat- I claim is l. A process of manufacturing ductile bodies of refractory metal, which consists in heating a single crystal of a metal in an at mosphere of a volatile and dissociable compound of the refractory metal at a temperature which is between that at which said compound dissociates andthat at which the dissociated metal ceases to associate with the metal of said crystal in such a way that the latter grows larger while retaining its single crystal structure.

2. A process of manufacturing ductile bodies of refractory metal, which consists in heating a single crystal of a metal in an atinosphcre of a volatile anddissociable compound of the refractory metal at a temperature which is between .that at which said compound dissociates and that at which the dissociated metal ceases to associate with the metal of said crystal, in such a way that the latter grows larger while retaining its single crystal structure, said Volatile and dissociable dompound being associated with a small quantity of another volatile substance, at

least one component of which substance will deposit with the dissociated refractory metal and together constitute the grown single crystal.

3. A process of manufacturing ductile bodies of refractory metal, which consists in heating a single crystal of a metal in a chamber through which passes a continuous flow of a volatilized dissociable compound of the refractory metal at a temperature which is between thatat which said compound dissociates and that at which the dissociated metal ceases -to associate with the metal of said crystal in such a way that the latter grows larger while retaining its single crystal structure.

4. A process of manufacturing ductile bodies of refractory metal, which consists in heating a single crystal of a metal in a chamber through which passes a continuous flow of a volatilized dissociable compound of the refractorymetal at a temperature which is between that at which said compound dissociates and that at which the dislatter grows larger while retaining its single 'crystal structure. said volatilized dissociable compound be ng associated with a small quantity of another volatile substance, at least one component of which substance will deposit with the dissociated refractory metal and together constitute the grown single crystal.

5. A process of manufacturing ductile bodies of refractory metal, which consists in heating a single crystal of a metal in an atmosphere of a. volatilized dissociable compound of the refractory metal and a nonmetallic radical at a temperature which is between that at which said compound dissociates and that at which the dissociated metal ceases to associate with the metal of said crystal in such a way that the compound breaks up and the refractory component is so deposited on the crystal that the latter grows larger while retaining its single crystal structure, and causing the non-metallic radical of the v olatilized dissociable compound to pass in contactrwith a separate body of the refractory metal at a temperature at which new quantities of the dissociable compound are reformed for a repetition of the cycle.

6. A process of manufacturing ductile bodies of refractory metal, which consists in T heating a single crystal of a metal in a chamber through which passes acontinuous flow of a volatilized dissociable compound of the refractory metal and a non-metallic radical at a temperature which is between that at which said compound dissociates and that at which the dissociated metal. ceases to associate with the metal of said crystal in such a way that the compound breaks up and the refractory component is so deposited on the crystal that the latter grows larger while retaining its single crystal structure, and cansing the non-metallic radical of the volatilized dissociable compound to pass in contact with a separate body of the refractory metal at a temperature at which new quantities of the dissociable compound are reformed for a repetition of the cycle.

7. A process of manufacturing ductile bodies of refractory metal, which consists in heating a single crystal of a metal in a. chamber through which passes a continuous flow ofa volatilized dissociable compound of the refractory metal and a non-metallic radical at a temperature which is betweenthat at which said compound dissociates and that at which the dissociated metal ceases to associate with the metal of said crystal, in

sueha way that the compound breaks up and the refractory component is so deposited on the crystal that the latter grows larger while retaining its single crystal structure, said volatilized dissociable compound being associated with a small quan tity of another Volatile substance, at least one component of which substance will deposit with the dissociated refractory metal and together constitute the grown single crystal, and causing the non-metallic radical of the volatilizeddissociable compound to pass in contact wit-h a separate body of the refractory metal at a temperature at which new quantities of the dissociable compound are reformed for a repetition'of the cycle.

8. A process of manufacturing ductile tungsten, which consists in heating a single crystal of tungsten in an atmosphere of avolatile and dissociable compound of tungsten at a temperature which is between thatat which said-compound dissociates and that at which the dissociated tungsten ceases to associate with the tungsten crystal, in such a way that the latter grows larger while retaining its single crystal structure. 7

9. A process of manufacturing ductile tungsten, which consists in heating a single crystal of tungsten in an atmosphere of a volatile and dissociable compoundof tungsten at a temperature which is betweenthat at which said compound dissociates and that at which the dissociated tungsten ceases to associate with the tungsten crystal, in such a way that the latter grows larger while retaining its single crystal structure, said volatile and dissociable tungsten compound being associated with a small quantity of another volatile substance, at least one component of which substance will deposit with the dissociated tungsten and together constitute the grown single crystal.

10. A process of manufacturing ductile tungsten, which consists in heating a single crystal of tungsten in a chamber through which passes a continuous flow of a volatilized dissociable compound of tungsten at a temperature which is between that at which said compound dissociates and that at which the dissociated tungsten ceases to associate with the tungsten crystal, in such a way that the latter grows larger while retaining its single crystal structure.

ILA process of manufacturing ductile tungsten, which consists in heating a single crystal of tungsten in a chamber through which passes a continuous flow of a volatilized dissociable compound of tungsten at a temperature which is between that at which said compound dissociates and that at which the dissociated tungsten ceases to as sociate with the tungsten crystal, in such a way that the latter grows larger while retaining its single crystal structure, said volatilized dissociable compound of tungsten be ing associated with a small quantity of another volatile substance, at least one component of which substance will deposit with the dissociated tungsten and together form the grown single crystal.

12. A process of manufacturing ductile tungsten, which consists in heating a single crystal of tungsten in a chamber through which passes a continuous flow of a volatilized dissociable compound of tungsten and.

a non-metallic radical at a temperature \Vll1Cl1.'lS between that at, which said compound dissociates and that at which the dis sociated tungsten ceases to associate with.

body of tungsten at a temperature at which new quantities of the dissociable tungsten compound are reformed for a repetition of the cycle.

13. A process of manufacturing ductile tungsten, which consists in heating a single crystal of tungsten in a chamber through which passes a continuous fiow of a Volatil- 'ized dissociable compound of tungsten and a non-metallic radical at a temperature which is between that at which said compound dissociates and that at which the dissociated tungsten ceases to associate wtih the metal of said crystal, in such a way that the compound breaks up and the refractory component is so deposited on the crystal that the latter grows larger while retaining its single crystal structure, said volatilized dissociable compound of tungsten being associated with a small quantity of another volatile substance, at least one component of which substance will deposit with the volatilized dissociated tungsten and together constitute the grown single crystal and causing the non-metallic radical of the volatilized dissociable compound to pass in contact with a separate body of tungsten at a temperature at which new quantities of the dissociable tungsten compound are reformed 'for a repetition of the cycle.

14. A process of manufacturing ductile tungsten, which consists in heating a single crystal of tungsten in an atmosphere of tungsten chloride to a temperature between 1200 C. and 2400" O.

15. A process of manufacturing ductile tungsten, which consists in heating a single crystal of tungsten in an atmosphere of tungsten chloride to a temperature between 1200 C. and 2400" 0., the tungsten chloride being associated with a small quantity of another volatile substance, at least one component of which substance will deposit with the dissociated tungsten of the tungsten chloride and together constitute the grown single crystal.

16. A process of manufacturing ductile eta tungsten. which consists in heating a single crystal of tungsten in an attnosphere of lEIHQ'STOILClllOlltlQ to a temperature between 1100' C. and Lttltl" C.. at which temperature the tungsten chloride is dissociated, the chlorine of said chloride passing in contact with a separate body of tungsten at a temperature at which new quantities of the tungsten chloride are reformed for a repetition of the cycle.

1?. A process of manufacturing ductile tungsten, which consists in heating a single crystal of tungsten in an atmosphere of tungsten chloride to a temperature between 1200" and ii l C. in such a way that the mnipound breaks up and the refractory .cmnponcnt is so deposited on the crystal that the crystal of tungsten growsdarger while retaining its single crystal form; the tungsten chloride being associated with a small quantity of. another volatile substance, at least one component of which substance will. deposit with the dissociated tungsten ot' the tungsten chloride and together constitute the grown single crystal, and cansing the chlorine of the dissociated chloride to pass in contact with a separate body of tungsten at a temperature at which new quantities of the tungsten chloride are rcformed for a repetition of the cycle.

18. A single crystal of a refractory metal having a diameter larger than 1 millimeter,

19. A smgle crystal of tungsten having a diameter larger than 1 millimeter.

90. Ductile refractory metal consisting of a single crystal of said refractory metal having a diameter larger than 1 millimeter and mechanically shaped into a form dif- 't'erent from that of the crystal.

21. Ductile tungsten consisting of a single crystal of tungsten having a diameter larger than t millimeter and mechanically shaped into a form difl'erent from that of the crystal.

2;. The process of increasing the size of a uuicrys'talline metal body which consists in pla' ing the hotly in a clauuber containing a chemical in gaseous form and in plac ing in the same chamber a separate mass of the same metal. heating the said mass to.

a sni'licient degree to cause the chemical to attack the said mass and form a gaseous compound with the metal and heating the uuicrystalline body to a degree sutticient to dissociate the metal from the chemical and to cause the dissociated metal to he deposited and added to the metal as a part of the unicrystalline body and thus rel asing the chemical for a repetition of the operation.

23. The process of causing the growth of a tungsten u'iicrystal which consists in heating the unicrystal to a temperature that will rob tungsten chloride of tungsten and liberate chlorine and in heating a mass of tung- ;ten to a ten'ipcrature that will cause the chlorine to unite with tungsten to form tungsten chloride and in enclosing the unicrystal and the said mass in a vessel eontaining chlorine and subjecting the mass to the action of the chlorine to form chloride of tungsten and subjecting the formed chloride of tungsten to the action of the unicrystal and to cause the deposit of tungsten upon the nnicrystal and cause the growth thereof, and subjecting the mass again to the liherated chlorine and repeating the c 'cle.

In testimony whereof I affix my signature.

ANTON EDUARD VAN ARKEL. 

